Documents /tmp cleanout workaround.
Documents /tmp cleanout workaround.

fixes gh-424

marbon87/spring-cloud-config,spring-cloud/spring-cloud-config,shakuzen/spring-cloud-config,shakuzen/spring-cloud-config,marbon87/spring-cloud-config,spring-cloud/spring-cloud-config,shakuzen/spring-cloud-config,marbon87/spring-cloud-config,spring-cloud/spring-cloud-config